Gas-Generating Polymer Particles: Reducing the Decomposition Temperature of Poly(tert-Butyl Methacrylate) Side Chains Using an Encapsulated Acid Catalyst Approach

We report an approach to gas-generating polymer particles based on the acid-catalyzed thermal decomposition of poly­(tert-butyl methacrylate) [p­(t-BMA)] side chains to isobutene gas. The decomposition temperature of t-BMA latex is near 191 °C and therefore impractical for many applications. The incorporation of select acid functionalized comonomers yields a decrease to ∼160 °C, as determined by thermal gravimetric analysis. This temperature can be further reduced to ∼120 °C, however, via encapsulation of a thermal acid generator. This approach exploits the favorable features of emulsion polymerization processes (rapid cycle times, particle size control, high conversion, etc.) and thus provides a framework for the fabrication of high-volume t-BMA-containing latex that can be used to light-weight and insulate composite materials through the creation of voids and pores. As such, gas-generating particles could reduce energy consumption needs in the transportation, construction, and other industries.